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Finish up ep 10 on macros

ep10
Sameer Rahmani 2 weeks ago
parent
commit
c29511a3cc
  1. 8
      core/fg42/cube.el
  2. 24
      core/fg42/flags.el
  3. 32
      docs/videos.org
  4. 1
      scripts/install_files.sh

8
core/fg42/cube.el

@ -29,12 +29,12 @@ @@ -29,12 +29,12 @@
(require 'fg42/utils)
(defvar fg42/after-cubes-setup-hook nil
"A hook that will be run after all the active cubes got setup. This hook
is dedicated for the codes that needs to do stuff based on other cubes
presence. With this hook we eliminate the need for cube ordering.
"A hook that will be run after all the active cubes got setup.
This hook is dedicated for the codes that needs to do stuff based on other cubes
presence. With this hook we eliminate the need for cube ordering.
It will be called in the `fg42-config' and the proper way to use
it is to use `fg42/after-cubes' macro. ")
it is to use `fg42/after-cubes' macro.")
(defvar fg42/available-cubes '()

24
core/fg42/flags.el

@ -90,9 +90,12 @@ For example, `(fg42/merge-flags (list f1 f2 f3) f4 -f2)' will return `(f1 f3 f4) @@ -90,9 +90,12 @@ For example, `(fg42/merge-flags (list f1 f2 f3) f4 -f2)' will return `(f1 f3 f4)
(defmacro defflag (flag-name docstring &optional default-value)
"Define a new flag FLAG-NAME with the given DOCSTRING.
If the DEFAULT-VALUE is a non nil value, then the flag will be
added to the activa flags list."
(let ((var-name (intern (format "fg42/-flag-%s" flag-name)))
(set-default (if default-value `((add-to-list 'fg42/flags ',flag-name)) ())))
added to the active flags list."
(declare (doc-string 2) (indent defun))
(let ((var-name (intern (format "fg42/-flag-%s" (symbol-name flag-name))))
(set-default (when default-value
`((add-to-list 'fg42/flags ',flag-name)))))
`(if (boundp ',var-name)
(warn (format "Flag name `%s' already defined" ,(format "%s" flag-name)))
(progn
@ -106,12 +109,11 @@ added to the activa flags list." @@ -106,12 +109,11 @@ added to the activa flags list."
(declare (indent defun))
;; The `cube-local-flags' variable here is going to be
;; defined in cubes to hold the local flags for each cube
(if (and (boundp 'cube-local-flags)
(member flag cube-local-flags))
`,@body
`(if (member ',flag fg42/flags)
,@body
nil)))
(if (not (and (boundp 'cube-local-flags)
(member flag cube-local-flags)))
`(progn ,@body)
`(when (member ',flag fg42/flags)
,@body)))
(defmacro if-flag (flag then else)
@ -121,8 +123,8 @@ added to the activa flags list." @@ -121,8 +123,8 @@ added to the activa flags list."
;; defined in cubes to hold the local flags for each cube
(if (and (boundp 'cube-local-flags)
(member flag cube-local-flags))
`,@then
`(if (member ',flag fg42/flags)
then
`(if (member ',flag fg42/flags)
,then
,else)))

32
docs/videos.org

@ -556,7 +556,8 @@ A collection of handy functions that operate on ~sequences~. @@ -556,7 +556,8 @@ A collection of handy functions that operate on ~sequences~.
#+END_SRC
- ~seq-min~, ~seq-max~
* Episode 9 - Introduction to Macros
* DONE Episode 9 - Introduction to Macros
CLOSED: [2022-09-11 Sun 11:08]
** What is a macro?
- A macro is defined much like a function
- It works on compile time
@ -598,7 +599,32 @@ A collection of handy functions that operate on ~sequences~. @@ -598,7 +599,32 @@ A collection of handy functions that operate on ~sequences~.
- [[https://twitter.com/lxsameer][@lxsameer]] on Twitter
* Episode 10 - More on Macros
** Quasiquotes aka back quote
** Quasiquote aka backquote (`)
- Backquote constructs allow us to quote an expression, but selectively evaluate sub-expressions
- Similar to a template engine for lisp expressions
- It can be used on its own but it will shine in macro definitions
- On the simplest form it is identical to ~quote~
- Special markers ~,~ and ~,@~ can be used to mark expressions for evaluation
- ~,~ will replace the return value of the evaluation with the expression
- ~,@~ will replace and splice the return value of the evaluation
*** Examples
#+BEGIN_SRC emacs-lisp
`3
`(1 2 3 4)
`(1 2 3 ,(+ 5 6))
`(1 2 3 ,(list 4 5 6))
`(1 2 3 ,@(list 4 5 6))
`(setq ,(intern (upcase "some_var")) 3)
#+END_SRC
** ~declare~ form
- It's a special macro which can be used to add meta properties to a function or macro
+ ~doc-string~
+ ~indent~
** Real Examples
Let's discuss ~defflag~ and ~when-flag~ macros in [[file:../core/fg42/flags.el]]
* Episode 11 - Common pitfalls of Macros
*

1
scripts/install_files.sh

@ -75,6 +75,7 @@ install_runners() { @@ -75,6 +75,7 @@ install_runners() {
info "Copying share files..."
sudo mkdir -p /usr/share/fg42/
sudo mkdir -p /usr/local/share/applications
sudo cp $fg42_home/share/applications/fg42.desktop /usr/local/share/applications
sudo cp -r $fg42_home/share/icons/hicolor/ /usr/local/share/icons
sudo cp -r $fg42_home/share/* /usr/share/fg42/

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